Research On High Performance Control Strategy Of Brushless Direct Current Motor

As science and technology develop rapidly,microprocessors’ price–performance ratio continues to increase,and its applications in the field of Brushless DC Motor(BLDCM)are becoming common.Using electronic components for motor commutation,BLDCM replaced traditional brush commutation,eliminating noise during operation.Furthermore,the service life of the motor was also increased,welcomed in various fields.With the advantages such as large electromagnetic torque,good speed regulation performance,simple control operation,BLDCM was used widely.Therefore,exploring the high-performance control strategy of BDLCM has always been a hot issue.Firstly,the structure,working principle,and mathematical model of BLDCM,as well as the control method,Field Oriented Control(FOC)and the modulation scheme,Space Pulse Width Vector Modulation(SVPWM),are introduced in the thesis.Then,the simulation models and waveforms of SVPWM was provided,verifying the correctness of the control strategy.The article focuses on optimizing the control algorithm.For the parameter limitation of traditional Proportional Integral(PI)controllers,the Sliding Mode Control(SMC)is used in the speed loop of the control system of BLDCM,and the simulation shows that SMC has better robustness than PI controllers.For the stator current oscillation,the proportional resonance(PR)control was used to replace the PI control of the current loop to effectively weaken the interference of higher harmonics of the stator current.The Simulation shows that the algorithm contributes to significant improvement of the system speed response.For better system performance,the SMC+PR composite control is introduced,and SMC application into the speed loop and PR control’s application into the current loop are proposed.The simulation shows a smooth current curve of the system,and the dynamic quality is significantly improved.Finally,the BLDCM control system platform is built based on the above theories and simulations,introducing the design of software and hardware in detail.Firstly,the FOC control strategy test is carried out on the hardware platform with STM32 as the core,and the test result is consistent with the simulations,which verifies the control scheme is effective.Then the motor speed waveforms under the four control algorithms are compared and analyzed,the SMC+PR compound control showing the best dynamic quality.